From bf5e4f554e5191a5af80540fb692658d181ed484 Mon Sep 17 00:00:00 2001
From: hippoz <10706925-hippoz@users.noreply.gitlab.com>
Date: Thu, 14 Apr 2022 21:32:52 +0300
Subject: [PATCH] backend/gateway: enforce `d` field to be a single numeric `0`
 for ping payloads

---
 src/gateway/index.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/gateway/index.ts b/src/gateway/index.ts
index c3e5a5e..fcc1c3f 100644
--- a/src/gateway/index.ts
+++ b/src/gateway/index.ts
@@ -216,7 +216,11 @@ export default function(server: Server) {
                     break;
                 }
                 case GatewayPayloadType.Ping: {
-                    // TODO: also check session here and ensure packet is sent at the right time
+                    if (payload.d !== 0) {
+                        return closeWithBadPayload(ws, "d: expected numeric '0'");
+                    }
+
+                    // TODO: also check session here
                     ws.state.alive = true;
                     break;
                 }